Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
sach van » sach han, sach va, bach van
van nang » van quang, van ban, van dong
vat hanh » vat thanh, van hanh, va hanh
hanh va » hang va, hanh vi
ve cham » va cham, ve chat, vu cham
so sach » so sanh, bo sach, co sach
mai hoi » mai khoi, dai hoi, lai hoi
lai roi » lai hoi, loi roi
ve cam » ve cac, va cam, ve cai
va cua » va chua, via cua, ca cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach van nang ((mai hoi) or (lai roi)). hieu ((ve cam) or (ve cham)) thuc vat hanh va cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach van nang ((mai hoi) OR (lai roi)). hieu ((ve cam) OR (ve cham)) thuc vat hanh va cua viet.
• Adding a wildcard symbol may retrieve word variants: so sach van nang ((mai hoi) or (lai roi)). hieu ((ve cam) or (ve cham)) thuc vat hanh va cua viet*.